Radio Resource Allocation for Mixed Latency UEs

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Solution Overview

Problem

The B4G TDD system lacks backward compatibility with existing LTE and LTE Advanced systems, making it difficult to communicate with legacy UEs that do not support low latency access.

Innovation Solution

A radio communication system that allocates a first plurality of time-frequency resources for legacy UEs and a second plurality of time-frequency resources with a shorter duration for UEs supporting low latency access, allowing both types of UEs to communicate effectively by using different transmission time intervals within the same subframe.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If a subframe structure with shorter TTI (e.g., 0.5 ms) is used to reduce access latency, then access latency is reduced, but backward compatibility with legacy UEs is lost

Engineering Contradiction:

Improveaccess latencyVSAvoidbackward compatibility

Core Design Contradiction:

Loss of timeVSAdaptability or versatility

Solution Approach 1:

The subframe is segmented into multiple slots, each slot being a separate TTI unit. This allows the system to support both short TTIs (one slot) and longer TTIs (multiple slots) within the same subframe structure, enabling legacy UEs to use longer TTIs while new UEs can utilize shorter TTIs for low latency access

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The TTI length is made dynamic and configurable per UE or per service type. The base station can flexibly adjust the TTI duration based on whether the UE is a legacy device or a new device supporting low latency, allowing the system to adapt to different requirements without fixing a single TTI length

Inventive Principle:

Principle #15Dynamics

2Device complexity

If a unified subframe structure is used for all UEs, then system complexity is reduced, but the ability to support both legacy and new UEs with different latency requirements is compromised

Engineering Contradiction:

Improvesubframe structure complexityVSAvoidmulti-UE compatibility

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The subframe structure is designed to be universal and multi-functional, serving both legacy UEs and new UEs simultaneously. By defining the subframe as containing multiple slots that can be independently configured, a single subframe structure achieves multiple functions: supporting long TTIs for legacy UEs and short TTIs for new UEs, thereby maintaining simplicity while enabling broad compatibility

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11974261B2Method, user equipment and access network node allocating resources in accordance with transmission time intervals

Publication Date: 2024.04.30 NEC CORP

AI summary

A radio station (3) allocates a first plurality of time-frequency resources (430) and a second plurality of time-frequency resources (530) to at least one radio terminal (1, 2). The first plurality of time-frequency resources (430) are used to transmit or receive a first transport block (460) in accordance with a first transmission time interval (TTI). The first TTI is equal to a duration of one subframe (410, 510). The second plurality of time-frequency resources (530) are used to transmit or receive a second transport block (560) in accordance with a second TTI. The second TTI is shorter than the duration of the subframe (410, 510).